Multicenter clinical trial that compares the therapeutic effectiveness and major economic costs of orally administered cefixime and a combination of intravenously administered cefotaxime plus oral cefixime in children one month to less than two years of age with urinary tract infection (UTI). The hypothesis is that there is no difference, as determined by specified outcome measures, between children one month to years of age, with bacteriologically confirmed UTI who receive specific oral antimicrobial therapy for 14 days (oral), and those who receive specific intravenous antimicrobial therapy for 4 days, followed by 10 additional days of oral therapy (parenteral). The study is intended to provide evidence that is sufficiently relevant and convincing to health care providers to guide their management of UTI in febrile children under two years of age. If results show no clinically significant differences in outcomes of oral and parenteral treatment of UTI, the use of the less costly treatment would be justified and because of the frequency with which UTI is treated in young children, would reduce costs significantly for medical care of this condition in the United States.